A week ago, my K8400 started having blockage issues while printing. After around 5 mins into every print the extruder starts to make jamming noises. Every time there is a small amount of molten filament in the top of the PEEK tube, blocking filament from coming through.
Picture of the PLA removed from the PEEK tube: imgur.com/sUJApBg
Is your 23mm tube cut perpendicular? Also I experienced that the peek is not always automatically centered under the tube fitting. So I fasten the bolts without tube fitting to check if the tube is centered beneath the tube fitting hole. If not the filament could get some friction on that point.
It happens mostly when the temperature is too high.
As the contact between the thermal sensor and the heater is far from optimal and the fan is blowing on it, the displayed temperature is well lower than the actual one.
So you should print PLA at 190° and ABS at 220° max (or even 210 depending on the color and brand).
[quote=“raby”]It happens mostly when the temperature is too high.
As the contact between the thermal sensor and the heater is far from optimal and the fan is blowing on it, the displayed temperature is well lower than the actual one.
So you should print PLA at 190° and ABS at 220° max (or even 210 depending on the color and brand).[/quote]
Thank you very much for your reply. All the prints were done with PLA at 190°C. Still the tube got blocked… Is it possible to go lower than 190°C?
Thank you very much I’ll try that!
[quote=“StrawberryJam”]Is it possible to go lower than 190°C?[/quote]It depends on how the sensor is positioned in the heater block, on how the small fan is blowing on it… The real temperature can vary a lot. The best melting temperature can also vary from brand to brand, even from color to color. It’s mostly a trial and error thing.
If the filament is softening before the nozzle then the temperature must be too high.
Try setting the retraction to 4mm retraction speed to 110mm in the Cura configuration.
The fans also need to be running at all times.
Thank you all very much for your suggestions! However I am still having the same problems… Nothing seems to help. I tried a print using the recommended retraction settings at 180°C (I even tried at 170°C) however still the same problem. Any ideas?
Just to be sure is the small fan on the print head running?
Try this to eliminate: Remove the tube and tube fitting from the printhead. Heat up the head manually (in Repetier) to 190 degrees. Take a piece of filament and try to push it slowly through the tube fitting hole. Then place the tube fitting and try it again. If the filament is smoothly coming out the nozzle, it’s not the printhead…
It seems like I fixed it… I replaced the small piece of PTFE tube leading to the nozzle and switched to another filament and it seems fine since then.
Thank you all very much for the help!! Have a great day!
Glad to hear it’s working again.
Enjoy!